In this specification the term “headlamp” or “headlamps” refers to the main light or lights (usually two) commonly fitted at the front of a car or other road vehicle. These commonly provide white light, but sometimes headlamps are tinted yellow. The term “headlight” is sometimes used interchangeably with headlamp, but more correctly the term “headlight” refers to the beam of light produced by a headlamp.
In this specification a reference to a road vehicle includes a reference to any road vehicle, including but not limited to cars, vans, buses, lorries and motorcycles, and a reference to a driver includes any driver including the rider of a motorcycle. References to road users include all road users including pedestrians.
Modern headlamps are electrically operated, and usually positioned in pairs, one or two on each side of the front of a vehicle. Most cars and other road vehicles are now fitted with headlamps which can be switched by the driver between a “high beam” (called a “main beam” or “full beam” or “driving beam” in some countries) and a “low beam” (sometimes called a “dipped beam). The high beam is brighter than the low beam, and the low beam is also commonly tilted down towards the road more than the high beam. The high beam is intended to illuminate a greater distance than the low beam, but the high beam is also more likely to dazzle oncoming road users.
The headlamps of many cars and other road vehicles are now operated using a stalk switch, hereinafter referred to as a “headlamp stalk”, which may be in the form of a pivoted stick or arm mounted just behind or below the steering wheel, for example mounted on the steering column. The headlamp stalk, which commonly also controls the turning indicators, allows the driver to select the main beam or low beam. The headlamp stalk may also be used to flash the headlamps.
The circumstances under which it is permitted to flash headlamps vary by jurisdiction. Examples of headlamp flashing which are nearly always permitted include warning another road user that their lights are not illuminated, or simply alerting another road user to your presence. There are other uses of headlamp flashing which occur frequently, including indicating that another road user may proceed, or thanking another road user for some action. This application is concerned with increasing the safety of headlamp flashes where such flashes occur for whatever reason.
When headlamps are flashed at another road user, particularly at night, the road user may become momentarily dazzled by the flashed high beam, particularly if the cars are approaching each other in opposite directions. The U.S. National Highway Traffic Safety Administration states that nearly half of all traffic-related fatalities occur in the dark, despite only 25% of traffic traveling during darkness.
In addition, a road user may misinterpret a headlamp flash as a rebuke, in the same way that the sounding of a horn may be misinterpreted. There is thus a need for a solution which addresses these issues.